EUCALYPTUS PRODUCTIVITY, SOIL PHYSICAL PROPERTIES AND ORGANIC MATTER FRACTIONS INFLUENCED BY TRAFFIC INTENSITY AND HARVEST RESIDUES
01/Jul/2015
The number of machine passes, types of wheels, and high soil moisture during harvest operations affect the soil compaction process. The impacts of these factors and alternatives to reduce them must be better understood. This study evaluated the impact of different traffic intensities of a loaded forwarder and the effect of different management conditions of eucalyptus harvest residues on productivity, soil physical properties, and organic matter at the end of the subsequent rotation in two Oxisols in the State of […]
NITROGEN LOSS BY EROSION FROM MECHANICALLY TILLED AND UNTILLED SOIL UNDER SUCCESSIVE SIMULATED RAINFALLS
01/Jul/2015
The description of the fate of fertilizer-derived nitrogen (N) in agricultural systems is an essential tool to enhance management practices that maximize nutrient use by crops and minimize losses. Soil erosion causes loss of nutrients such as N, causing negative effects on surface and ground water quality, aside from losses in agricultural productivity by soil depletion. Studies correlating the percentage of fertilizer-derived N (FDN) with soil erosion rates and the factors involved in this process are scarce. The losses of […]
TOTAL ORGANIC CARBON AND SOIL AGGREGATION UNDER A NO-TILLAGE AGROECOLOGICAL SYSTEM AND CONVENTIONAL TILLAGE SYSTEM FOR ONION
01/Jul/2015
As a result of soil management systems, like the conventional tillage system (CTS) versus the no-tillage system (NTS) for vegetable crops, modifications in soil properties occur, which change, for example, the rates of soil aggregation and the content of total organic carbon (TOC). The aim of this study was to quantify the TOC contents and evaluate the rates of soil aggregation and the distribution of aggregates by diameter classes in a soil planted to onion in NTS and CTS and […]
Changes in the Structure of a Nigerian Soil under Different Land Management Practices
01/May/2015
Quantification of soil physical quality (SPQ) and pore size distribution (PSD) can assist understanding of how changes in land management practices influence dynamics of soil structure, and this understanding could greatly improve the predictability of soil physical behavior and crop yield. The objectives of this study were to measure the SPQ index under two different land management practices (the continuous arable cropping system and natural bush fallow system), and contrast the effects of these practices on the structure of PSD […]
Air Permeability of the Soil Seedbed under a No-Tillage System
01/May/2015
Air permeability may be used as a soil physical quality indicator. The objective of this study was to determine the air permeability and pore continuity index for the seedbed of an Oxisol cultivated under a no-tillage system that underwent mechanical chiseling and biological promotion of pore formation using the forage radish crop. The study was carried out in an experimental area of the Universidade Estadual de Ponta Grossa (Ponta Grossa State University), Parana, Brazil. The treatments were 18 consecutive years […]
Soil Properties and Carbon Accumulation in an Integrated Crop-Livestock System Under No-Tillage
01/May/2015
In production systems such as the integrated crop-livestock system (ICL) under no-tillage, improvements have been observed in chemical, physical, and biological soil properties. Therefore, we aimed to evaluate the changes in chemical and physical soil properties, as well as carbon (C) accumulation, in an Oxisol under irrigated conditions in the Cerrado (Brazilian tropical savanna) in an ICL system under no-tillage. The experiment was carried during the growing of 2010/2011, 2011/2012, and 2012/2013. A randomized block experimental design with four replications […]
Grazing Height of Brachiaria and Stocking Rate Limited by Soil Physical Properties Three Years Into an Integrated Soybean Crop-Livestock System
01/May/2015
Management of forage grazing height by cattle may compromise soil physical properties. The objective of this study was to evaluate the influence of grazing height of brachiaria (Urochloa ruziziensis) and the average stocking rate, after three years into an integrated soybean crop-livestock system, in the physical attributes of a Haplorthox (Rhodic Ferralsol). A randomized complete block experimental design with three replications was used. Five treatments were evaluated in 1 ha experimental plots: grazing heights of 10, 20, 30, and 40 […]
Soil Aggregation, Organic Carbon Concentration, and Soil Bulk Density As Affected by Cover Crop Species in a No-Tillage System
01/May/2015
Soil aggregation and the distribution of total organic carbon (TOC) may be affected by soil tillage and cover crops. The objective of this study was to determine the effects of crop rotation with cover crops on soil aggregation, TOC concentration in the soil aggregate fractions, and soil bulk density under a no-tillage system (NTS) and conventional tillage system (CTS, one plowing and two disking). This was a three-year study with cover crop/rice/cover crop/rice rotations in the Brazilian Cerrado. A randomized […]
Soil Load-Bearing Capacity in Orange Grove Conservation Systems
01/May/2015
Conservation tillage systems in orange groves can increase soil load-bearing capacity minimizing their risks of soil compaction. The objective of this study was to evaluate load-bearing capacity through preconsolidation pressure and its dependence on water content, bulk density, and organic carbon of a Typic Paleudult soil 18 years after setting up permanent plant cover between the rows of an orange grove. A randomized block experimental design was used, with three replications. Three groundcover treatments subjected to mowing between the rows […]
EFFECT OF SOIL TILLAGE AND PLANT RESIDUE ON SURFACE ROUGHNESS OF AN OXISOL UNDER SIMULATED RAIN
01/Jan/2015
Surface roughness of the soil is formed by mechanical tillage and is also influenced by the kind and amount of plant residue, among other factors. Its persistence over time mainly depends on the fundamental characteristics of rain and soil type. However, few studies have been developed to evaluate these factors in Latossolos (Oxisols). In this study, we evaluated the effect of soil tillage and of amounts of plant residue on surface roughness of an Oxisol under simulated rain. Treatments consisted […]